This viaduct is located on the High-Speed Railway Line between Madrid and Extremadura. The overall length of the viaduct is 1,488 metres. The span distribution is dictated by the Tagus River crossing, which is performed using a 324 m span arch. The deck over the arch is divided into six 54 m long spans. The approach spans are 60 m long, with two, inserted, 57 m long transition spans at the abutments on either side of the arch.
The emblematic element of the viaduct is the arch itself. It has a curved directrix and is comprised of a box girder whose depth ranges from 3.50 m to 4.00 m and which is 12.00 m wide at the abutments and 6.00 m wide at midspan.
Its 324 m long main span will surpass in length by 60 metres the Bridge over the Contreras Reservoir, the longest high-speed railway concrete arch bridge built in Spain to date.
The two approach spans are clearly different in what regards the distance existing between the ground and the gradient. While on the left bank the elevation is a mere 23 m just 140 m away from the river-edge, on the left bank this value is reached as far as 600 m away from the river-edge. This will affect the design of the main bridge´s approach viaducts. The position of their embedding on both riversides is almost fixed, given the fact that the land is quite level on the right river bank and hence it makes no sense to increase the arch span.
The overall viaduct length is 1,488 metres and its span distribution is 45 + 9×60 + 57 + 324 + 57 + 7×60 + 45 m.
The deck cross section is made up of a prestressed concrete, 4.00 m deep box girder. Such slenderness makes it possible to adequately span the 60 m lengths of the approach spans plus the 54 m lengths over the arch, which, due to its flexibility, introduces additional bending moments. The width of the lower slab is 5.00 m while that of the upper one is 6.50 m, with cantilevers that complete the total 14.00 m width of the cross section. The thickness of the webs amounts to 0.50m. The characterisation of concrete is HP-50 in the approach viaduct spans and HP-70 in the spans over the arch.
